Oriole, Inc., has collected the following information on its cost of electricity:

		Machine Hours		Total Electricity Costs
January		510		$240
February		540		$300
March		350		$190
April		440		$200
May		670		$260
June		710		$350
July		300		$170
August		500		$260
September		220		$121
October		740		$320
November		840		$400
December		600		$300

Using the high-low method, compute the variable cost of electricity per machine hour. (Round unit cost to 2 decimal places, e.g. 52.75.)

Variable cost is $.___ Per machine hour.